Did you not read this bit.Fy21Ap tests in a funjet that i've built for a mate

I didn't know anything about the Fy21Ap till i started putting it in the funjet. Im actually very impressed with it. the altitude hold feature works perfectly. in fact the whole lot works perfectly. You just have to respect what it can and cant do. You still need to be aware of what your doing, and i agree with you Steve the FY21Ap isn't a 'get out of jail free card' In any FPV flight you need to have some sort of plan so you dont drain your battery with not enough juice to come home.